40 REPORT OF THE COMMISSIONER OF FISHERIES. 



perch, and yellow perch can be very materially increased in all the 

 Great Lakes if sufficient funds for the establishment and operation 

 of new field stations can be obtained. 



CULTIVATION OF FISHES OF MINOR INTERIOR W^\TERS. 



The active and increasing demand for fishes for lakes, ponds, and 

 interior streams has in general been met by the various stations de- 

 voted to the trouts, landlocked salmon, basses, crappies, sunfishes, 

 etc. As a rule, the applications for such fishes can be promptly filled, 

 but the production of smallmouth black bass has never been equal to 

 the demand, and the regular output of brook trout has had to be sup- 

 plemented by the purchase of large numbers of eggs from private 

 fish-culturists. 



The stations in the Eocky Mountain region in Montana, Wyo- 

 ming, Utah, Colorado, and South Dakota have handled the native 

 trouts and two introduced trouts, together with grayling, and the 

 season's output was of average volume. 



In the Montana field, with the Bozeman station as headquarters 

 and with hatcheries in Yellowstone National Park and Glacier Na- 

 tional Park as auxiliaries, the varied operations have been success- 

 ful. The collections of rainbow-trout eggs in Madison Valley, aggre- 

 gating 3,812,000, were only a little below^ the record take of the pre- 

 vious year, and grayling eggs to the number of 700,000 were obtained 

 in the same field. 



At the hatchery on Yellowstone Lake, in Yellowstone National 

 Park, some of the eggs of the blackspotted trout taken from wild fish 

 are incubated and the resulting young are deposited in park waters, 

 while limited consignments of eyed eggs are made to the Bozeman 

 hatchery and to the fish commissions of the States of Montana, 

 Wyoming, Idaho, Oregon, and Washington. During the season of 

 1920, which involves the end of the fiscal year 1920 and the begimiing 

 of .the fiscal year 1921, about 6,500,000 eggs were taken. In the sum- 

 mer of 1919 the Commissioner made a personal inspection of the 

 fish-cultural work in the park, and made arrangements for extend- 

 ing and augmenting the hatching operations in view of the very 

 heavy drain on the fish life occasioned by the greatly increased 

 number of anglers now resorting to the park. The superintendent 

 of the park has extended every facility for making the hatchery 

 effective and for enabling the Bureau to maintain and improve the 

 supply of fish in the park waters. 



The auxiliary hatchery in Glacier National Park, constructed for 

 the National f*ark Service, but operated by the Bureau of Fish- 

 eries, has already justified its establishment. Encouraging reports 

 are being received as to the results of this pioneer work, and it is 

 believed that in a short time noteworthy collections of eggs may be 

 obtainable from waters entirely devoid of fish life previous to the 

 Bureau's entry into this field. The fiscal year's hatching operations 

 in the park extended from July 1 to September 30, 1919, and from 

 April 29 to June 30, 1920. The eggs handled consisted of 300,000 

 brook trout from tthe Leadville station, 310,000 rainbow trout from 

 the field station in Madison Valley, 500,000 grayling obtained through 

 the courtesy of the Montana Fish and Game Commission, and 200,000 



